Windows 10/1511, Movie Maker 2012 just updated.

I've begun my movie with static image with text, added 15 or more clips with extension .mts, edited and inserted transitions. Played and saved project all in same folder. It all worked fine last week. Today I open project, it all loads, click play and and not all of my clips are playing. They look complete in my work area, but when played or time line is slid across them they are blank/black screens. Some play correctly and some don't.

I followed advice I found to repair Windows Essentials, reopen Movie Maker but have same problem. 

I have also re-booted my machine.